HomeMy WebLinkAbout6 - Evaluation of Water Treatment Fluoridation ChemicalsCITY OF BOULDER
WATER RESOURCES ADVISORY BOARD
AGENDAITEM
MEETING DATE: May 21, 2007
AGENDA TITLE: Evaluation of Water Treatment Fluoridation Chemicals
PRESENTER/S:
Robert E. Williams - Director of Public Work for Utilities
Randy Crittenden - Water Treatment Coordinator
Suzanne Givler - Process Optimization Specialist
EXECUTIVE SUMMARY:
This report is a staff evaluation of available fluoride-containing water treatment additives.
Currently City of Boulder water is fluoridated using fluorosilicic acid. Sodium
silicofluoride is a dry fluoride-containing water treatment additive that has fewer
contaminants than fluorosilicic acid. Both products meet all regulations.
Sodium silicofluoride can be purchased as 50-pound bags or as 2,000- or 2,500-pound
supersacks. The cost to convert the City of Boulder feed system to a dry feed system that
can feed sodium silicofluoride is estimated to be:
AGENDA ITEM # PAGE
Total O eration and Maintenance Cost for Each Fluoride Chemical
Chemical Capital Cost, including O&M Cost: Chemical,
forklift training and Labor, Forklift Training,
res irator ro ram Res irator Trainin
Fluorosilicic Acid $38,750 fortank $68,600
replacement + unknown (chemical cost only)
extras + piping, unknown
date
Sodium Fluoride Bag $847,100 $107,000
S stem
Sodium Silicofluoride Bag $847,100 $63,400
System ($5,200 chemical savings
over FSA
Sodium Fluoride $1,049,100 $102,100
Su ersack S stem
Sodium Silicofluoride $1,049,100 $60,000
Supersack System ($8,600 chemical savings
over FSA
STAFF RECOMMENDATION:
None at this time.
COUNCIL FILTER IMPACTS:
None at this time.
OTHERIMPACTS:
None at this time.
BOARD AND COMMISSION FEEDBACK:
No action requested at this time.
PUBLIC FEEDBACK:
None at this time.
ANALYSIS:
None at this time.
MATRIX OF OPTIONS:
Please see attached report.
ATTACHMENTS:
City of Boulder Water Treatment Fluoride Additive Evaluation and Appendices
AGENDA ITEM # PAGE
City of Boulder Water Treatment
Fluoride Additive Evaluation
May 2007
Staff:
Ned Williams, Director of Public Works for Utilities
Randy Crittenden, Water Treatment Coordinator
Suzanne Givler, Process Optimization Specialist
p. 1
Fluoride Additive Evaluation
May 2007
INTRODUCTION
The City of Boulder has added fluoride to municipal drinking water since voters approved
fluoride addition in 1969. From 1969 until the 1990s, the chemical used for fluoride addition was
sodium silicofluoride, a dry crystalline chemical supplied in 50-pound bags. Brown and Caldwell
Consultants stated in the 1990 City of Boulder Treated Water Master Plan, Phase L•
The existing fluoride feed system requires bags of fluoride to be manually
emptied into a hopper. This is a very labor intensive practice, and the employee
responsible for handling the bags may be exposed to excessive fluoride dust.
Also, ventilation in the bag feed room is inadequate for dust control.
It is recommended that the existing fluoride feed system be replaced with a
system utilizing a bulk storage system with automatic feed.
In 1993 improvements were completed to the Betasso Water Treatment Plant that allowed for
bulk storage and feeding of fluorosilicic acid, a liquid fluoride chemicaL These improvements
were completed for the Boulder Reservoir Water Treahnent Plant (a.k.a. 63`d Street Water
Treatment Plant) in 1998.
In 2007, City staff reviewed current fluoridation practices and researched advantages and
disadvantages of switching to another fluoridation chemical.
REGULATIONS
The Colorado Department of Public Health and Environment, Design Criteria for Potable Water
Systems, requires that "any chemical additives or materials that come in contact with the water
will be certified under the ANSI standard 60 or 61, respectively." The American National
Standards Institute (ANSI) accredits the National Sanitation Foundation (NSF) to develop
American National Standards.
NSF/ANSI Standard 60 covers chemicals which are used to treat drinking water, and NSF/ANSI
Standard 61 covers devices, components, and materials which come into contact with drinking
water.
For contaminants regulated by the EPA, the NSF/ANSI Standard 60 sets a single product
allowable concentration not to exceed ten percent of the Maximum Contaminant Level (MCL).
The single product allowable concentration is the concentration of the contaminant present at the
tap in any wnsumer's home. Thus, any fluoridation chemicals meeting NSF/ANSI Standard 60
will never add greater than one-tenth of the MCL of any contaminant to finished water.
There are three fluoride-containing water treatment additives that aze approved for use under the
NSF/ANSI Standard 60: Drinking Water Treatment Chemicals. These are fluorosilicic acid,
p. 2
sodium silicofluoride, and sodium fluoride. Pure fluoride ion solutions are not available. Fluorine
is the most reactive of all the elements and elemental fluoride is never found by itself in nature.
The City of Boulder further specifies that that the fluorosilicic acid supplied must conform to
AWWA Standard B703-00. AWWA has been developing standards since 1908 that are used
throughout the world. Although conformance to AWWA standazds is not mandatory, they are
industry standards that many utilities and regulatory agencies choose to enforce.
The Colorado Deparhnent of Public Health and Environment (CDPHE) sets the Maximum
Contaminant Level (MCL) and the Maximum Contaminant Level Goal (MCLG) for fluoride in
drinking water at 4.0 mg/L. The EPA defines an MCL as "the highest level of a contaminant that
is allowed in dririlcing water. MCLs are set as close to MCLGs as feasible using the best
available treatment technology and taking cost into consideration. MCLs are enforceable
standards." The EPA defines an MCLG as "the level of a contaminant in drinking water below
which there is no known or expected risk to health. MCLGs allow for a margin of safery and are
non-enforceable public health goals."
The CDPHE sets the Secondary Maximum Contaminant Level (SMCL) for fluoride at 2.0 mg/L.
SMCLs are not enforceable and are intended as guidelines for chemicals that primarily affect the
aesthetic qualities of drinking water. When the fluoride level exceeds the SMCL, public
notification is required.
CHEMICALS
Fluorosilicic Acid (aka Fluosilicic Acid or Hydrofluorosilicic Acid or FSA):
According to "Water Fluoridation and the Environment: Current Perspective in the United
States," published in the October, 2004 International Journal of Occupational and
Environmental Health, roughly 59% of communities fluoridating their water supply use
fluorosilicic acid and about 63% of citizens drinking fluoridated water are drinking water treated
with fluorosilicic acid. Kip Duchon, Fluoridation Engineer at the Center for Disease Control,
reported in 2006 that, currently, closer to 77% of the fluoride market is for fluorosilicic acid.
The AWWA standard for fluorosilicic acid is standard B703-00. AWWA Standazd B703-00 does
not specify a maximum allowable heavy metal concentration for fluorosilicic acid.
The City of Boulder feeds fluorosilicic acid provided by Lucier Chemical Industries (LCI) in
Jacksonville Beach, Florida (see Appendix A for a~list of other Front Range communities feeding
fluorosilicic acid. See Appendix B for a picture of the fluorosilicic acid feed system at Betasso
Water Treatment Plant). LCPs Product Data Sheet states that their fluorosilicic acid heary
metals concentration (as Lead) will never exceed 200 mg/L.
Certificates of Analysis provided with product deliveries in 2006 and 2007 show the following
concentrations of arsenic and lead:
p. 3
Date of
Anal sis Date of Delivery Arsenic Concentration
m Lead Concentration
m
5/22/06 6/7/06 - Betasso 20.75 <1 undetectable
6/9/O6 6/26/06 - 63` 26.00 <1 undetectable
7/3/06 7/27/06-Betasso 30.75 <I undetectable
1/31/07 2/13/07-Betasso 45.50 <1 undetectable
4/2/07 4/24/07 - Betasso In anal sis 12.7
An arsenic concentration of 45.5 mg/L can result in a maximum estimated finished water arsenic
addition of 0.18 µg/L (see Appendix C for caiculations). The maximum contaminant level for
arsenic specified by the EPA is 10 µg/L. A lead concentration of 12.7 mg/L can result in a
maximum estimated finished water lead addition of 0.05 µg/L (see Appendix C for calculations).
The action level for lead specified by the EPA is 15 µg/L.
In September 2005, the Colorado DepaRment of Public Health and Environment published "A
Message from the Prevention Services Division to Public Water Systems that Fluoridate" which
states:
On September 1, 2005, the Colorado Department of Public Health and
Environment (CDPHE), Prevention Services Division, Oral Health Unit notified
all Community Public Water Systems (PWS) in the State that fluoridate the public
drinking water they produce that there may be a potential disruption to their
fluoride supply, and provided recommendations to maximize their current
supplies. The Centers for Disease Control and Prevention (CDC) has identified
that there is a disruption to the fluoride products market, resulting in the potential
for shortages. A major producer of hydrofluorosilicic acid, U.S. Agrichemicals, is
withdrawing from the market, and remaining producers do not have sufficient
fluoride recovery capacity to replace the lost production.
In 2007, Kip Duchon (CDC) reported that the shortage was temporary, and other producers are
now filling the need for fluorosilicic acid.
The Ciry of Boulder's cost for fluorosilicic acid has changed as follows:
Year Cost per ton % Increase
er ton Annual cost % Increase in
annual cost # of deliveries
er ear
2005 $268.00 $29,162 4 Bet, 1 63`
2006 $391.00 45.9% $39,094 341% 2 Bet , 1 63`
2007 $500.00 27.9% 2 Bet to date
In 2006 and before, fluorosilicic acid deliveries arrived approximately four to ten days after they
were ordered by city staf£ In 2007 city staff was notified by LCI that this could increase to 21
days.
p. 4
The City's fluorosilicic acid tanks have an expected life of 20 years and the piping has an
expected life of 10 years. The tank and piping at Betasso Water Treahnent Plant is 14 years old
and the tank and piping at Boulder Reservoir Water Treatment Plant is 9 years old. The City of
Fort Collins also feeds fluorosilicic acid and has a similar feed system. They replaced their tank
at 14 years and their feed piping at less than 10 years. Estimated costs for tank replacement aze
$21,250 for the Betasso tank and $17,500 for the Boulder Reservoir tank. These costs are for the
tank only and not for any additional parts such as nozzles, ladders, etc. It is unclear whether these
costs include assembly of the tank onsite.
Sodium Silicofluoride (aka Sodium Fluorosilicate):
According to the October, 2004 article from the International Journal of Occupational and
Environmental Health, roughly 163% of communities fluoridating their water supply use
sodium silicofluoride and about 28.2% of citizens drinking fluoridated water are drinking water
treated with sodium silicofluoride. Kip Duchon (CDC) reported in 2006 that, curcently, 15% of
the fluoride market is for sodium silicofluoride.
The AWWA standard for sodium silicofluoride is standard B702-99. This standard requires that
sodium silicofluoride have a heavy metal concentration of less than 500 mg/L.
Sodium silicofluoride is used by several Front Range communities (see Appendix A for a list of
communities). Denver Water, who uses sodium silicofluoride at two of their three plants,
forwarded to Ciry staff two analyses performed on their product that showed the concentration of
the three heavy metals of interest to all be below detection limits of the method used:
Date of Analysis Arsenic
Concentration m Lead Concentration
m /L Method Used
7/4/03 <1 Q ICP
9/19/06 <2 <2 ICP-OES
An arsenic concentration of 2 mg/L can result in a maatimum estimated finished water arsenic
addition of 0.003 µg/L (see Appendix C for calculations). The maximum contaminant level for
arsenic specified by the EPA is 10 µg/L. A lead concentration of 2 mg/L can result in a
maximum estimated finished water lead addition of 0.003 µg/L (see Appendix C for
calculations). The action level for lead specified by the EPA is 15 µg/L.
Kip Duchon (CDC) repoRed in 2007 that when U.S. Agrichemicals withdrew from the market in
2005, about half of U.S. sodium silicofluoride supplies began to be impoRed from a producer in
China. This resulted in longer lead times when ordering sodium silicofluoride but not a big cost
increase.
Staff at Denver Water reported that the cost of their chemical increased 5% from 2006 to 2007,
and the lead time required when placing an order increased from 3-4 weeks in 2006 to 8-12
weeks in 2007. Denver Water feeds sodium silicofluoride in bulk. The City of Longmont uses
sodium silicofluoride 50-pound bags. They reported that the cost of their chemical did not
increase much between 2006 and 2007, but the lead time required when placing an order had
p. 5
gone from approximately one week to approximately four weeks. A sales representative at a
major sodium silicofluoride producer, KC Industries, reported that base cost per ton went from
$560 in 2006 to $616 in 2007, a 10% increase. He further reported that cost per ton would
increase at least $40 per ton as of July 1, 2007 due to increasing costs of raw material, such as
fluorosilicic acid, and energy.
Sodium in drinkin wg ater:
Addition of sodium silicofluoride would add up to approximately 037 mg/L of sodium to the
finished water (see Appendix C for calculations).
Sodium data for Betasso and the Reservoir Water Treatment Plants is as follows:
Betasso Water Treatment Plant
Sam le Location Date Sodium m Source
Betasso Finished Water * 5/9/06 3.8 18 cfs Lakewood
9 cfs Barker
Betasso Filter Flume ll/29/OS 1.5 6 cfs Lakewood
5 cfs Barker
* Sample location changed
63'd Street Water Treatment Plant
Sam le Location Date Sodium m
63` Boulder Reservoir Basin I/2/07 6.0
63` Boulder Reservoir Basin 12/4/06 5.9
63` Boulder Reservoir Basin 11/21/06 5.8
63` Boulder Reservoir Basin 6/5/06 6.8
63` Boulder Reservoir Basin 4/4/06 10.6
63` Boulder Reservoir Basin 3/6/06 9.6
63` Boulder Reservoir Basin 1/31/O6 9.9
63` Boulder Feeder Canal 10/2/06 5.8
63` Boulder Feeder Canal 9/5/06 2.4
63` Boulder Feeder Canal 8/21/06 2.5
63` Boulder Feeder Canal 10/3/OS 3.2
63` Finished Water 5/9/06 18 Basin source
63` Finished Water 11/29/OS 14.8 Basin source
The EPA has set a sodium Drinking Water Equivalent Level (DWEL) of 20 mg/L. This DWEL
is defined in the EPA's Contaminant Candidate List Regulatory Determination Support
Document jor Sodium (2003) as "a non-enforceable guidance level considered protective against
non-carcinogenic adverse health effects and is based on an American Heart Association
recommendation issued in 1965." However, EPA states on their Sodium in Drinking Water
webpage (httn~//www epa ~ov/safewater/contaminants/unreeulated/sodium.html), "EPA believes
this guidance level for sodium needs updating, and is probably low. If a health benchmark for
p. 6
drinking water were established using current information and current drinking water health
assessme~t procedures, it would likely be higher °
EPA does not regulate sodium with a National Primary Drinking Water Regulation. In the
Contaminant Candidate List Regulatory Determination Support Document for Sodium it is stated
that this is because the EPA has found that regulation "may not present a meaningful opportunity
for health risk reduction for persons served by public water systems." This document further
states, regarding hypertension and sodium regulation:
"The weight of evidence favors the conclusion that high sodium intakes can have
an adverse effect on blood pressure, especially for sodium-hypertensives.
Hypertension affects almost 50 million people in the United States, and along
with factors such as body weight, alcohol intake, and cholesterol, is a risk factor
for heart disease. However, hypertension is influenced more by lifesryle,
behavior, and other nutrient intake than by sodium intake.
"Sodium is known to occur in public water systems and in a few cases at levels of
public health concem, particularly for salt-sensitive hypeRensives. However, at
these same concentrations, taste is generally affected and would likely lead
consumers to decrease consumption. In addition, when compared with other
intake routes, sodium from drinking water has a minor impact. For these reasons,
regulation of sodium is unlikely to present a meaningful opportunity for health
risk reduction for persons served by public water systems. However, EPA may
choose to issue a non-enforceable Drinking Water Advisory, based on current
health effects, taste effects, and occunence data, to provide guidance to
communities that may be exposed to elevated concentrations of sodium chloride
or other sodium salts in their drinking watec In addition, under EPA-required
sodium monitoring, test results must be reported to State and local public health
autharities, who may advise sensitive populations of any risk they may face: '
The State of Colorado requires annual monitoring for sodium. However, there is no Maximum
Contaminant Level, Secondary Contaminant Level, Treatment Technology, or Action Level for
sodium specified by the State.
Sodium fluoride:
According to the October, 2004 article from the International Journal of Occupational and
Environmental Health, roughly 24.9% of communities fluoridating their water supply use
sodium fluoride and about 9.2% of citizens drinking fluoridated water are drinking water treated
with sodium fluoride. Kip Duchon (CDC) reported in 2006 that, currently, 8% of the fluoride
market is for sodium silicofluoride.
The AW WA standard for sodium fluoride is standard B701-99. This standazd requires that
sodium fluoride have a heavy metal concentration of less than 400 mg/L.
p. 7
Thatcher Chemical, a company that supplies sodium fluoride, informed City staff that the
manufacturer (in China) reported typical heary metal concentrations in the sodium fluoride of 50
mg/L lead and 40 mg/L arsenic. Ciry staff was unable to obtain any analyses of sodium fluoride
showing actual heavy metals concentrations.
The Town of Hayden in Colorado in northwest Colorado uses sodium fluoride. They reported
that the cost of their chemical did not increase between 2006 and 2007. Also, the lead time
required to place an order did not increase. Their orders are relatively small, at approximately 20
bags per order.
Sodium fluoride is more expensive than the other dry form, sodium silicofluoride (see Appendix
A for estimated chemical costs).
Pharmaceutical Qrade
Sodium fluoride is also available in ACS/Reagent (American Chemical Society) and USP (U.S.
Pharmaceutical) grades. ACS/Reagent grade chemicals aze generally intended for laboratory and
other analytical applications. USP grade chemicals are suitable for food, drug, or medicinal use
and also may be used for most laboratory purposes. NSF grade chemicals are specifically
intended for use in drinking water and thus specify that any contaminant regulated by the EPA be
specifically tested for and meet certain criteria.
Sodium fluoride meeting ACS specifications must have a heavy metals (as Pb) concentration of
less than 30 mg/L. Sodium fluoride meeting USP specifications also must have a heavy metals
(as Pb) concentration of less than 30 mg/L. USP-grade sodium fluoride is a powder. The AWWA
standard for sodium fluoride specifies that a coazse crystalline grade be used. Using the USP-
grade powder could potentially create mare dust, which is a hazard to water treatment plant
operators. It is the understanding of City staff that there aze no communities feeding ACS- or
USP-grade sodium fluoride.
It is uncleaz whether ACS- or USP-grade sodium fluoride could be purchased in the quantities
required in order to be used as the fluoride source by the City of Boulder.
It is possible that the Colorado Department of Public Health and the Environment would approve
feeding ACS- or USP-grade sodium fluoride even though these grades do not meet NSF/ANSI
certification. Kip Duchon (CDC) reported in 2007 that "the biggest concern and motivation for
NSF certification was to ensure maintenance of the product quality during chemical delivery, for
it has been documented that the overwhelming amount of impurities occur as a function of
transport and distribution. USP provides no protection during distribution and transportation. My
opinion is that USP provides much less protection for the consumer." He further reported that, of
the three grades of sodium fluoride available (NSF, USP, and ACS), "Each is slightly different,
but they result in a comparable level of impurities."
p. 8
Sodium in drinkinQ water:
Addition of sodium fluoride would add up to approximately 1.1 mg/L of sodium to the finished
water (see Appendix C for calculations). (See further discussion about sodium above)
SODNM SILICOFLUORIDE SELECTED FOR FUTHER CONSIDERATION
Sodium silicofluoride is the least expensive of the fluoridation chemicals used in water treatment
and it is used by several municipalities along the Front Range. Thus, City staff selected sodium
silicofluoride for further consideration.
PRICING FOR CONVERSION TO SODIUM SILICOFLUORIDE
Black and Veatch developed a wst estimate for converting the existing fluorosilicic acid feed
systems to dry chemical feed systems (see Appendix D for Black and Veatch's full report).
Sodium silicofluoride may be purchased as 50-pound bags or as 2500-pound or 1-ton supersacks
(see Appendix B for a picture of a bag feed system and a supersack feed system).
Black and Veatch determined that the existing chlorine scrubber room at Betasso Water
Treatment Plant could be used to house the feed equipment and two pallets of fluoride. An
additional storage building would be needed to house additional pallets. Black and Veatch
determined that the existing chlorine scrubber room at the Boulder Reservoir Water Treatment
Plant is sufficient to house the feed equipment and all pallets.
Bag Feed System
Costs provided by Black and Veatch for addition of a dry fluoride bag feed system include the
cost for renovation of the scrubber rooms; new feed equipment including a dry feeder, storage
hopper, solution tank, two pumps, piping, electrical, and instrumentation; storage racks for dry
fluoride pallets; elevated feed platforms; and a new building at Betasso Water Treatment Plant.
Costs were estimated as:
Item Cost
Betasso Water Treatment Plant: Renovation of Scrubber Room $155,800
Betasso Water Treatment Plant: New Stora e Buildin $92,000
Reservoir Water Treahnent Plant: Renovation of Scrubber Room $149,500
Contin enc 40% $159,000
General re uirements 10% $56,000
TOTAL $613,000
In addition, the City of Boulder would need to purchase two forklifts for moving and lifring
pallets. Final project capital costs estimated by Black and Veatch were:
p. 9
Total Ca ital Cost for Conversion to D Chemical Ba Feed S stem
Betasso Water Treatrnent Plant Construction Cost $382,000
63` Street Water Treatment Plant Construction Cost $231,000
Two Owner Purchased Forklifrs $53,000
En ineerin Costs desi n, bid, construction administration, ins ection $133,000
TOTAL $799,000
Black and Veatch estimated 2007 fluoride chemical costs as:
Chemical 2007 Estimated Chemical Cost
Fluorosilicic Acid $68,600
Sodium Fluoride $ 75,200
Sodium Silicofluoride $33,100
Black and Veatch estimated increased operation and maintenance costs of a dry fluoride bag feed
system due to operators manually loading bags of fluoride into the storage hoppers as:
Chemical Number of 50-Lb. Ba s O&M
Sodium Fluoride 2300/ ear $4,900/ ear
Sodium Silicofluoride 1730/ ear $3,350/ ear
Final operation and maintenance wsts estimated by Black and Veatch compared to operation and
maintenance costs for the current fluorosilicic acid feed system were calculated as:
Annual O eration and Maintenance Cost for Each Chemical
Chemical Chemical Cost O&M Cost Annual Cost
Fluorosilicic Acid FSA $68,600 $0 $68,600
Sodium Fluoride bag
s stem $75,200 $4,900 $80,100
Sodium Silicofluoride
ba s stem $33,100 $3,350 $36,450 ($32,150
savin s over FSA
Supersack System
Kip Duchon (CDC) recommended to City staffthat the supersack system be considered to
minimize handling and labor issues if the City decides to switch to sodium silicofluoride.
Costs provided by Black and Veatch for addition of a dry fluoride supersack system include the
cost for renovation of the scrubber rooms; new feed equipment including a dry feeder, solution
tank, superstructure, two pumps, piping, electrical, and instrumentation; storage racks for dry
fluoride pallets; and a new building at Betasso Water Treatment Plant. Costs were estimated as:
p. 10
Item Cost
Betasso Water Treatment Plant: Renovation of Scrubber Room $208,750
Betasso Water Treatment Plant: New Stora e Buildin $92,000
Reservoir Water Treatment Plant: Renovation of Scrubber Room $206,250
Contin enc 40% $203,000
General re uirements 10% $71,000
TOTAL $781,000
As for the bag feed system, the City of Boulder would need to purchase two forklifrs for moving
and lifting pallets. Final project capital costs estimated by Black and Veatch were:
Total Ca ital Cost for Conversion to D Chemical Su ersack Feed S stem
Betasso Water Treatment Plant Construction Cost $463,000
63` Street Water Treatment Plant Construction Cost $318,000
Two Owner Purchased Forklifts $53,000
En ineerin Costs desi n, bid, construction administration, ins ection $167,000
TOTAL $1 001,000
Final operation and maintenance costs estimated by Black and Veatch compared to operation and
maintenance costs for the current fluorosilicic acid feed system were calculated as:
Annual O eration and Maintenance Cost for Each Chemical
Chemical Chemical Cost O&M Cost Annual Cost
Fluorosilicic Acid $68,600 $0 $68,600
Sodium Fluoride
su ersack s stem $75,200 $0 $75,200
Sodium Silicofluoride
su ersack s stem $33,100 $0 $33,100 ($35,500
savin s over FSA
Black and Veatch indicated in their report that sodium fluoride supersack systems are somewhat
rare and thus the chemical cost used in the above table may be incorcect.
Forklift Training
A forklift will be required at each plant for unloading pallets from the truck at deliveries, moving
the pallets to a storage area, and then moving them when they are ready to be used. For a bag
system, the pallets are lifred onto a platform from which operators can empty bags into the dry
feed hopper. For a supersack system, the supersacks are lifred from the pallets onto the dry
feeders.
OSHA requires that operators attend a training class that will certify them to operate the forklifts.
There are two types of classes. Individual operator training costs $85.00 per student and is a half-
day class. Alternatively, one person can be trained to train others for $795.00 for a full-day class.
p. 11
Forklift training costs were determined for 17 employees: 13 operators and 4 maintenance staff.
It was assumed that training would be done onsite at one of the plants on two different days, so
that only 10 employees (6 night operators and 4 day operators) would have to come in at a time
that is not during their regular shifr. The following tables summarize the cost estimates:
Initialfork-ift trainin costs
Trainin costs Overtime costs Total costs
Individualoperator $1145 $1440 $2585
trainin costs: 17 o erators 10 o erators, 4 hours each
Train the trainer: $795 $1728 $2523
1 operator (I operator, 8 hours, plus
10 o erators, 4 hours each
Forklift training would be required for any new operators. Assuming that a new operator would
have to travel to the forklift dealership for training at a time that is not during their regular shift,
the cost would be approximately $373 for training costs and salary. In 2005, there was one new
operator hire and one internal transfer to operations. In 2006, again there was one new operator
hire and one internal transfer to operations. This is an average of two new operators per year, for
a total estimated ongoing forklifr training cost of $746 per year.
Respirator program
Material Safety Data Sheets for sodium silicofluoride specify that respirators should be worn
when handling the chemical.
Poms & Associates Insurance Brokers, Inc., a company that has worked regulazly with the City
of Boulder in the area of risk assessment and safety training, listed the steps for implementation
of a respirator program as:
1. Workplace assessment. This includes air sampling at both plants.
2. Respirator selection for specific chemicals in use.
3. Medical evaluations of affected staff. The minimum requirement for the first year of a
respirator program is a pulmonary function and fit test for approximately $150 per
person. However Poms & Associates recommends a full pulmonary physical and a fit test
in the first yeaz for employee health and safety.
4. Staff training - recognizing hazards, respirator use and maintenance.
5. Annual Fit testing, as well as fit testing for new employees or chemicals. The minimum
requirement for subsequent years is a fit test for approximately $50 per person. However
Poms & Associates recommends a full pulmonary physical in addition to a fit test each
year for employee health and safety.
Costs were determined for 21 employees: 13 operators, 2 backup operators, 4 maintenance staff,
and 2 supervisors. The following tables summarize the cost estimates:
p. 12
Estimated startu costs:
Air sam lin at both lants $6000
Poms & Associates providing the Ciry with respirator program $4800
paperwork, and a Poms & Associates consultant working onsite to
act as a technical advisor, overseeing monitoring, coordinating
vendors and quotes, assisting with medical requirements setup, and
conductin initial trainin : 40 hours total
Pulmona h sicals for 21 em lo ees: $300 er erson $6300
Fit tests for 21 em lo ees: $50 er erson $1050
Respirators: 11 full face ($300 each) and 10 positive air flow ($500 $8300
each for bearded staff inembers
Res irator cartrid es $30-40/set and dis osal $6000
Lon len h rubber loves for cuttin ba s: 10 sets 5 er lant $160
Lightweight Rubber-Coated Cloth Aprons for cutting bags: 10 (5 $115
er lant
Tyvek Cleanroom Garments for covering clothing during $1000
maintenance:50 azments 25 er lant
TOTAL $33,725
Annual o eration and maintenance costs.•
Annual ulmona h sicals and fit tests for 21 em lo ees $7350
Program review and refresher training: 40 hours onsite by Poms &
Associates consultant $4800
Res irator carnid es $30-40/set and dis osal $6000
Lon len h rubber loves for cuttin ba s: 10 sets 5 er lant $160
Lightweight RubberCoated Cloth Aprons for wtting bags: 10 (5
er lant $115
Tyvek Cleanroom Garments for covering clothing during
maintenance:50 arments 25 er lant $1000
Time of an internal ro ram administrator Unknown
TOTAL $19,425
Poms & Associates further recommended that an additional I S% be added to final cost estimates
for contingencies, plus an additional 20% for unknown and unforeseeable issues. This gives final
estimated costs o£
Estimated startup costs:
Annual operation and maintenance costs:
$45,500
$26,200
p. 13
Grants
The Colorado State Fluoridation Program administers federal funds known as Preventative Block
Funds. In 2007, the State is expecting to receive $10,000 -$15,000 for this use. The general
purpose of these funds is to encourage new plants to install fluoridation. However, State staff
said that if the Ciry of Boulder switches to a new fluoride chemical and applies for these funds,
the app-ication will be considered based on availability of funding at the time.
The Colorado Department of Local Affairs administers Community Development and
Community Services Block Grants. However, these grants are intended for projects that
primarily benefit low/moderate income persons and may not be applicable to the City of
Boulder.
CONCLUSIONS
City staff reseazched available fluoridation chemicals and their costs in order to determine if a
different chemical may result in higher water quality. City staff focused on sodium silicofluoride
because of its low cost, common use in the Front Range area, and low heavy metals
contamination. Estimated costs for each chemical are:
Total O eration and Maintenance Cost for Each Fluoride Chemical
Chemical Capital Cost, including O&M Cost: Chemical,
forklift training and Labor, Forklift Training,
res irator ro ram Res irator Trainin
Fluorosilicic Acid $38,750 tank cost + extras + $68,600
i in , unknown date
Sodium Fluoride Bag $847,100 $107,000
S stem
Sodium Silicotluoride Bag $847,100 $63,400
S stem $5,200 savin s
Sodium Fluoride Supersack $1,049,100 $102,100
S stem
Sodium Silicofluoride $1,049,100 $6Q000
Su ersack S stem $8,600 savin s
p. 14
Aoaendices
Appendix A
Appendix B
Appendix C
Appendix D
Fluoride Chemical Comparison
Fluoride Feed System Pictures
Fluoride Concentration Calculations
Black and Veatch's City of Boulder Dry Fluoride Feasibility Study
p. 15
City of Boulder Water Treatment
Fluoritle Chemical Comparison
Sodium silicofluorida Sodium fluoride Fluorosilieic Acid
Grade NSF-certified NSFceNified Pharmaceutical rede NSFcertified
Granular.
Chemical form (specified by Available in 50-pound bags and Powder.
AW WA standard, where 2000-pound or 2500-pound Coarse crysfalline. Available in sizes up to 250- Liquid.
a licable su ersacks Available in 50- ound ba s ounds Available in bulk
90% domestically produced
Location of manufacture (predominantty by Mosaic Co.),
(source: Kip Duchon, CDC 5% imported from Mexico, 100% imported from Asia, mostly 100°k imported from Asia, mostly 50 b domeshcally produced.
Fluoridation En ineer, 2007 5°~ im orted from Canada from China from China 50% im rted from China
Heavy metals
confamination levels:
AW WA sWndard < 5D0 m as Pb < 400 m as Pb NA Does not s eci
LCI: < 200 ppm as Pb.
Typical As <40 ppm. AGUaI LCI 2006-2007 analyses:
Typical 2 ppm as Pb. Typical Cd < 20 ppm. From manufacturer 20.75 ppm < As < 45 5 ppm;
Typical eontamination LCI/Denver analyses 2003, 2006: Typical Pb < 50 ppm. Max heavy metals 30 ppm as Pb < 1 ppm;
levels As, Cd, Pb undetectable No actual anal ses data lead Cr = 50 m
Meets ANSI-NSF 609 Yes Yes No Yes
Meefs SWte standards9 Yes Yes No Yes
A roximate °/ Fluoride lon 59 44 44 19
Li uidlSlur H 3.5-4.0 7.0 7.0 10-12
stimate annualamounto
chemical required for City
of Boulder (2006 chemical 37,700 kg 50,500 kg 50,500 kg
usa e a 4.5 ba s er da tota7 av 6.1 ba s er da total av 1.2 ba s er da total 119,700
s6ma annua c em ca
cost for City of Boulder
(2006 chemical usage, 2007
cost $31,800 $72,300 $1,053,800 $66,000
Denver (Foothills, Moffal),
Longmont, Lafayette, Louisville,
Fort CoUins, Greeley, Loveland, None along the Front Range.
Front Range communities Brighton, Arvada, Broomfeltl, Hayden (northwest Colorado) is Boulder, FoA Collins, Denver
that use this roduct Su erior the Gosest knOwn communi . None Marston , Aurora, Arvada
Venlilation, respirator, gloves, Ventilation, respirator, gloves, Ventilation, respirator, gloves, Ventilalion or breathing
Personal Protectfon goggles, dust impervious safety glasseslface shield, boo[s, safety glasses/face shield, boots, protection. Gioves, glasses/face
E ui ment Re uired. rotedive suit. coveralls coveralls shield, overalls, boots.
Respirator treining
re uiredl Yes Yes Yes Onl maintenance ersonnel
APPENDIX A
Ciry of Boulder Water Treatment
Fluoride Feed System Pictures
Current feed system: Fluorosilicic Acid (Betasso pictured)
_ , ~Y ~ ~
~
1. ~
L 1
~
~
. ~
' ~_• ~
.... ' ~
~ 1
1
:7, (, +~' ~''a
_ ~ ~ 0.~0
I ~- : rr~~ - ~ , .
~3• ~ ~ ~ ~ L
_ _.:'~f ~ ~
.~ ':~*i~ + • 2:. ,g ~''~~ ~ ~~
f~ -~~".. ~,~~ 'L~ t il ~ ~ J
Appendix B P• 1
Ciry of Boulder Water Treatment
Fluoride Feed System Pictures
Appendix B p. 2
Example dry chemical bag system (LongmonYs sodium silicofluoride feed system pictured)
Ciry of Boulder Water Treatment
Fluoride Feed System Pictures
Appendix B
p. 3
Dry chemical supersack system (activated carbon feed system pictured with 2000 or 2500 pound
supersacks. Courtesy of Black & Veatch).
Note that each plant would only require one feeder.
MIN
MAX
MAX
City of Boulder Water Treatment
Fluoride Concentration Calculations
Date
Fluoride - m ll Boulder Reservoir Water Treatm
Total FI FSA ent Plant
Sodiu 63rd St.
m Silicofluoride Sodium Fluoride
Raw Finished Added
(mg/L) mL FSA
per L
treated
water As
~9«' Lead uglL' ml
Na2SiF6
per L
treated As or Pb
~9/~` Sodium
Added
(mg/L) ml NaF
per L
treated
water As
~9/~° Sodium
Added
(mg/L)
1!1/2004 0.28 0.99 0.71 0.0031 0.140 0.0391 0.0010 0.0019 0.2865 0.0013 0.052 0.8595
211/2004 0.23 0.91 0.68 0.0029 0.134 0.0374 0.0009 0.0019 0.2744 0.0012 0.050 0.8232
7!8l2004 0.24 0.92 0.68 0.0029 0.134 0.0374 0.0009 0.0019 0.2744 0.0012 0.050 0.8232
812/2004 0.29 0.88 0.59 0.0026 0.116 0.0325 0.0008 0.0016 0.2381 0.0011 0.043 0.7142
9/1l2004 0.38 1.04 0.66 0.0029 0.130 0.0363 0.0009 0.0018 0.2663 0.0012 0.048 0.7989
4/1/2005 0.27 0.95 0.68 0.0029 0.133 0.0372 0.0009 0.0018
0015 0.2730
0
2159 0.0012
0010
0 0.049
0
039 0.8191
0
6476
714l2005 0.33 0.87 0.54 0.0023 0.105 0.0294 0.0007 0. . . . .
10/2/2005 0.17 0.88 0.71 0.0031 0.139 0.0388 0.0010 0.0019 0.2845 0.0013 0.052 0.8534
11/1/2005
12/1l2005 0.22
0.22 0.83
0.96 0.61
0.74 0.0026
0.0032 0.119
0.146 0.0333
0.0407 0.0008
0.0010 0.0016
0.0020 0.2441
0.2986 0.0011
0.0014 0.044
0.054 0.7324
0.8958
1/11/2006 0.27 0.92 0.65 0.0028 0.127 0.0355 0.0009 0.0018 0.2603 0.0012 0.047 0.7808
2/2/2006 0.24 0.91 0.67 0.0029 0.132 0.0369 0.0009 0.0018 0.2704 0.0012 0.049 0.8111
3/1/2006 0.29 1.01 0.72 0.0031 0.142 0.0396 0.0010 0.0020 0.2905 0.0013 0.053 0.8716
4/1/2006 0.29 0.91 0.62 0.0027 0.121 0.0338 0.0008 0.0017 0.2482 0.0011 0.045 0.7445
5l1I2006 0.31 0.95 0.64 0.0028 0.126 0.0352 0.0009 0.0017 0.2582 0.0012 0.047 0.7747
6!1/2006 0.25 0.86 0.61 0.0026 0.119 0.0333 0.0008 0.0016 0.2441 0.0011 0.044 0.7324
7/3/2006 0.22 0.89 0.67 0.0029 0.131 0.0366 0.0009
0011
0 0.0018
0021
0 0.2683
3147
0 0.0012
0014
0 0.049
O
OS7 0.8050
9442
0
8/712006
9/1/2006 0.16
0.21 0.94
0.94 0.78
0.73 0.0034
0.0032 0.154
0.144 0.0429
0.0402 .
0.0010
0
0011 .
0.0020
0
0021 .
0.2946
0
3147 .
0.0013
0
0014 .
0.053
0
057 .
0.8837
9442
0
10/2/2006
1 ~/1 l2006 0.20
0.23 0.98
0.89 0.78
0.66 0.0034
0.0029 0.154
0.130 0.0429
0.0363 .
0.0009 .
0.0018 .
0.2663 .
0.0012 .
0.048 .
0.7989
12l1 /2006 0.21 0.83 0.62 0.0027 0.122 0.0341 0.0008 0.0017 0.2502 0.0011 0.045 0.7505
1/2/2007 0.30 0.98 0.68 0.0029 0.134 0.0374 0.0009 0.0019 0.2744 0.0012 0.050 0.8232
APPENDIX C
p. 1
MIN
MAX
MIN
City of Boulder Water Treatment
Fluoride Concentration Calculations
Betasso Water Treatm ent Plant
Date Fluori de - m/l Total FI FSA Sodiu m Silicoflu oride Sod ium Flu oride
Raw Finished Added
(mg/L) mL FSA
per L
treated
water As
ug~~' Lead ug/L2 m~
Na2SiF6
per L
treated As ug/L' SODIUM
ADDED
(mglL) ml NaF
per L
treated
water As
ug/L' Sodium
Added
(mglL)
111l2004 0.13 0.95 0.82 0.0036 0.162 0.0451 0.0011 0.0022 0.3309 0.0015 0.060 0.9926
4/1l2004 0.11 0.87 0.76 0.0033 0.150 0.0418 0.0010 0.0021 0.3067 0.0014 0.056 0.920~
5/1/2004 0.09 0.95 D.86 0.0037 0.170 0.0473 0.0012 0.0023 0.3470 0.0016 0.063 1.0411
6/1/2004 0.12 0.91 0.79 0.0034 0.156 0.0435 0.0011 0.0022 0.3188 0.0014 0.058 0.9563
7/1/2004 0.08 0.88 0.80 0.0035 0.158 0.0440 0.0011 0.0022 0.3228 0.0015 0.058 0.9684
1111l2004 0.19 0.90 0.71 0.0031 0.140 0.0391 0.0010 0.0079 0.2865 0.0013 0.052 0.8595
1/1/2005 0.10 0.87 0.77 0.0033 0.152 0.0424 0.0010 0.0021 0.3107 O.OD14 0.056 0.9321
6/1 /2005 0.10 0.99 0.89 0.0038 0.175 0.0487 0.0012 0.0024 0.3571 0.0016 0.065 1.0713
8/1/2005 0.11 0.96 0.85 0.0037 0.168 0.0468 0.0012 0.0023 0.3430 0.0016 0.062 1.0289
9/1J2005 0.10 0.84 0.74 0.0032 0.146 0.0407 0.0010 0.0020 0.2986 0.0014 0.054 0.8958
12l312005 0.11 0.90 0.79 0.0034 0.156 0.0435 0.0011 0.0022 0.3188 0.0014 0.058 0.9563
1/1/2006 0.07 0.98 0.91 0.0039 0.179 0.0501 0.0012 0.0025 0.3672 0.0017 0.066 1.1016
4/2l2006 0.12 0.91 0.79 0.0034 0.156 0.0435 0.0011 0.0022 0.3188 0.0014 0.058 0.9563
5/2/2006 0.09 0.80 0.71 0.0031 0.140 0.0391 0.0010 O.OU19 0.2865 0.0013 0.052 0.8595
6/1/2006 0.~8 0.89 0.81 0.0035 0.159 0.0443 0.0011 0.0022 0.3248 0.0015 0.059 0.9745
8l1/2006 0.07 0.84 0.77 0.0033 0.151 0.0421 0.0010 0.0021 0.3087 0.0014 0.056 0.9261
9/1/2006 0.11 0.85 0.74 0.0032 0.146 0.0407 0.0010 0.0020 0.2986 0.0014 0.054 0.8958
11l1/2006 0.08 0.87 0.79 0.0034 0.156 0.0435 0.0011 0.0022 0.3188 0.0014 0.058 0.9563
12/1l2006 0.13 0.82 0.69 0.0030 0.136 0.0380 0.0009 0.0019 0.2784 0.0013 0.050 0.8353
1/1/2007 0.09 0.86 0.77 0.0033 0.152 0.0424 0.0010 0.0021 0.3107 0.0014 0.056 0.9321
APPENDIX C
p. 2
City of Boulder Water Treatment
Fluoride Concentration Calculations
1- Using 45.5 ppm arsenic concentration in fluorosilic acid - from COB 1-07 certificate of analysis -~~vORST CASE
2- Using 12.7 ppm lead concentration in fluorosilicic acid - from COB 4-07 certificate of analysis - WORST CASE
3- From City of Denver's analysis September 2006: As < 2 ppm and Pb < 2 ppm
4- From typical As concentration provided by Thatcher Company: As < 40 ppm, Pb < 50 ppm
Arsenic MCL = 10 ug/L
Arsenic MCLG = 0 ug/L
Lead Action Level (no MCL) = 0.015 mg/L = 15 uglL
Lead MCLG = 0 ug/L
mL FSA added per liter of treated water =
= dose / dens I %fluoride ion =
= mg F- ' mq H2SiF6 ' mg HFS " mL HFS = mL HFS
L treated water mg F- mg H2SiF6 1234 mg HFS L treated water
ug As added per liter of treated water =
= mL HFS '
L treated water
mq As ' 1 L ' 1000 uQ = uc1 As
L HFS 1000 mL 1 mg L treated water
APPENDIX C P 3
City of Boulder
Dry Fluoride Feasibility Study
Black 8 Veatch Corporation
Centennial, Colorado
Project No. 744922.230
May 2007
DRAFT
Contents
Paae
1.0 Introduction and Purpose ........................................................................ 1
2.0 Preliminary Investigations and Alternative
Selection ................................................................................................. 3
3.0 Selected Alternatives .............................................................................. 3
3.1 Betasso WTP Layout and Construction
Cost Estimate ............................................................................... 3
3.2 Boulder Reservoir WTP Layout and
Cost Estimate ............................................................................... 5
3.3 Operation and Maintenance Costs ............................................... 6
4.0 Summary .................................................................................................6
~aaszz.zao TC-1 osnaio~
DRAFT
Tables
Paae
Table 1 Year 2007 Estimated Fluoride
Chemical Costs ............................................................................ 6
Table 2 Summary of Capital Costs for
Conversion to Dry Fluoride ........................................................... 7
Table 3 Annual Operation and Maintenance
Cost Differential for Dry Fluoride Use
Compared to Fluorosilicic Acid ..................................................... 7
Figures
Following
Page
Figure 1 "Supersack" Dry Chemical Feeders ............................................. 1
Figure 2 Renovation of Existing Scrubber
Rooms for Manually Loaded Dry
Fluoride System ............................................................................ 2
Figure 3 Renovation of Existing Scrubber
Rooms for Supersack Dry Fluoride
Feed Systems .............................................................................. 2
Appendices
Appendix A Detailed Cost Estimates
144922.230 TCi-2 OS/14/07
DRAFT
City of Boulder
Dry Fluoride Feasibility Study
1.0 Introduction and Purpose
The City of Boulder (the City) currently fluoridates finished water at its
Betasso and Boulder Reservoir Water Treatment Plants (WTPs) using
fluorosilicic acid. Flurorosilicic acid is delivered to the WTPs in liquid form and is
fed neat (as delivered, undiluted) into the finished water. Due to increasing
concerns in regards to the addition of trace contaminants contained within water
treatment chemicals, the City is considering alternative forms of fluoride that
have lower trace contaminant levels. These alternative forms include sodium
fluorosilicate and sodium fluoride, both of which are dry (powder/granular)
chemicals. Generally, sodium fluoride has the lowest level of trace
contaminants, while fluorosilicic acid has the highest. However, this can be
manufacturer specific, especially when dealing with the dry forms. The main
contaminants within fluoride type chemicals are heavy metals, such as lead,
cadmium, chromium, and arsenic. It is important to note that the City's current
fluoridation program does not exceed any water treatment regulations in regards
to heavy metal contaminant levels.
The purpose of this study is to determine whether existing space at both
the Betasso and Boulder Reservoir WTPs can be utilized to store and feed dry
fluoride or if new buildings would need to be constructed. Two dry fluoride
systems were considered. The first type of system utilizes 50-pound bags that
are manually loaded into a hopper that is connected to the dry feeder and
solution tank. The second system uses 2,000- or 2,500-pound "supersacks" that
are directly hooked into the dry feeder (see Figure 1). This type of system
requires a fairly large superstructure that encapsulates the hoisting mechanisms,
dry feeder, and solution tank.
Once the determination was made as to the location of the new dry
chemical feed and storage areas, feasibility level floor plans and cost estimates
were prepared. Lastly, an operation and maintenance (O&M) cost comparison
between all three chemicals was completed.
144922230 ~ OS/14/07
DRAFT
2.0 Preliminary Investigations and Alternative Selection
Each of the WTPs has an existing chlorine scrubber room available for
use as the new dry fluoride feed and storage areas if the space permits it. The
City no longer uses gaseous chlorine; therefore, there is no need for the existing
scrubbers. A site visit and review of these available rooms at both the WTPs
was conducted on April2, 2007. The site visit included reviewing the most
up-to-date drawings and comparing them to the current layout of the scrubber
rooms. Potential for forklift access into each of the rooms from outside and the
turning radius required inside the room was also investigated since the dry
fluoride will be delivered and stored on pallets (fifty, 50-pound bags or one
"supersack" per pallet). Height of the ceilings in each room was also considered
for the "supersack" type feeders, since these can be as tall as 15 to 17 feet. The
City completed preliminary feed calculations and determined that a truckload
consisting of 17 pallets could be split between the two plants. This amount of dry
fluoride would be sufficient to provide at least a one month supply of dry fluoride
at the maximum feed rate and maximum WTP flow rates as determined by the
City.
After the review, the determination was made that the scrubber room at
the Betasso WTP was only large enough to house the feed equipment and two or
three pallets of fluoride (a standard pallet is 40 inches by 48 inches). An
additional 20-foot by 20-foot storage building to house the remainder of the
pallets will need to be constructed. The Boulder Reservoir WTP scrubber room
is sufficient in size to house both the feed equipment and store eight pallets.
3.0 Selected Alternatives
Feasibility level configurations for the dry chemical fluoride feed facilities
are described in the following sections.
3.7 Betasso WTP Layout and Construction Cost Estimate
The scrubber room at the Betasso WTP is approximately 17.5 feet by
20.0 feet and has access from the outside of the building that is at grade with
stair landings inside the building. The basic layouts for renovations of this room
are shown on Figure 2 for the 50-pound bag system and Figure 3 for the
"supersack" system. The main components and design considerations of these
layouts include the following:
144922230 2 05/74/07
DRAFT
Figure 1-"Supersack" Dry Chemical Feeders
. Add additional support under the existing stairway landings in order
to accommodate the forklift and pallet loads.
. Install a new concrete operating floor to the extents shown on
Figures 2 and 3.
. Set the new feed equipment in the "piY' at Elevation 6410.67 feet.
The feed equipment would include a dry feeder, solution tank,
storage hopper (for the 50-pound bag manually loaded system
only), superstructure (for the "supersack" system only), and two
feed pumps (one duty, one standby).
. Install a two-tier, single-bay steel storage rack to house two pallets
of dry fluoride. This would help to eliminate the need to
continuously bring in pallets from the storage building, especially in
the event of bad weather. A forklift would be used to transfer dry
chemical pallets from the storage rack to the feeding platform or to
locate the "supersacks" under the hoist. The installation of this
small storage rack would not hinder the forklift turning radius in
order to load a pallet onto the feeding platform.
• 50-Pound Bag Manual Loaded System Only. Install a steel or
aluminum feeding platform large enough to accommodate one
pallet of dry fluoride. Note that this elevated platform is needed
because the estimated height of the feed hopper is expected to be
approximately 9 feet above the floor elevation.
In addition to renovation of the existing chlorine scrubber room, a small
storage building will need to be constructed to accommodate any additional
pallets of fluoride. This building would not need to be any larger than 20 feet by
20 feet and would need to match the existing architecture at the WTP.
Estimated construction costs for the manually fed and "supersack" type
systems are $382,000 and $463,000, respectively. Detailed cost estimates are
included in Appendix A, Tables A-1 and A-2. An industry standard 40 percent
contingency is included at this feasibility level.
144922.230 3 OS/14/07
DRAFT
3.2 Boulder Reservoir WTP Layout and Cost Estimate
The scrubber room at the Boulder Reservoir WTP is approximately
18.5 feet by 28.5 feet. Current access from outside into the scrubber room is by
stairs that access a door approximately 2 feet above the outside grade. The
basic layouts for renovations of this room are shown on Figures 2 and 3. The
main components and design considerations of this layout include the following:
. Demolition of the existing stairs and walkway inside of the scrubber
room. The new operating floor would be at the current lowest level
(Elevation 5165.50 feet) of this room.
. Install a new concrete landing and stairs to the extents shown on
Figures 2 and 3.
. Set the new feed equipment at an Elevation 5165.50 feet. The feed
equipment would include a dry feeder, solution tank, storage
hopper (for the 50-pound bag manually loaded system only),
superstructure (for the "supersack" system only), and two feed
pumps (one duty, one standby).
. Install a two-tier, three-bay steel storage rack to house six pallets of
dry fluoride. Two additional pallets could be stored in front of the
storage rack.
. Demolition of outside stairway and landing, lower existing
threshold. and install new door.
. 50-Pound Bag Manual Loaded System Only. Install a steel or
aluminum feeding platform large enough to accommodate one
pallet of dry fluoride. Note that this elevated platform is needed
because the estimated height of the feed hopper is expected to be
approximately 9 feet above the "piY' elevation.
Estimated construction costs for the manually fed and "supersack" type
systems are $231,000 and $318,000, respectively. Detailed cost estimates are
included in Appendix A, Tables A-3 and A-4. An industry standard 40 percent
contingency is included at this feasibility level.
144922.230 4 05/74/07
DRAFT
3.3 Operation and Maintenance Costs
The main 08~M costs associated with any chemical feed system are the
cost of the chemical themselves. The City provided Black & Veatch Corporation
(Black & Veatch) with fluorosilicic acid usage information that indicated there was
a 4 percent increase in usage from 2005 to 2006. Using this increase, along with
cost data that the City also supplied, the yearly costs of using each of the
chemicals was calculated for anticipated 2007 usage (see Table 1).
Table 1
Year 2007 Estimated Fluoride Chemical Costs
Chemical 2007 Chemical Cost
1$)
Fluorosilicic Acid 68,600
Sodium Fluoride 75,200
Sodium Fluorosilicate 33,100
In addition to the chemical costs, the only anticipated difference between
liquid fluoride and dry fluoride feed costs would be that of the WTP operators
having to manually load bags of fluoride into the storage hoppers for the
50-pound bag manually fed type system. Using the same usage information
provided by the City, a labor cost associated with this activity was calculated.
These costs were calculated at $4,900 per year and $3,350 per year for sodium
fluoride and sodium fluorosilicate, respectively. The difference in the costs is
attributed to the fact that sodium fluoride contains a lesser amount of fluoride ion
per pound; therefore, more pounds of chemical per year will be utilized.
4.0 Summary
Table 2 summarizes the capital costs that would be required to convert the
City's current liquid fluoride feed and storage systems to that of dry fluoride feed
and storage. Table 3 summarizes the anticipated O&M cost differential of using
sodium fluoride or sodium fluorosilicate versus fluorosilicic acid.
iaaszz zao 5 osnaio~
DRAFT
Table 2
Summary of Capital Costs for Conversion to Dry Fluoride
System Capital Cost
1$)
50-Pound Bag Manually Loaded System
Betasso WTP Construction Cost 382,000
Boulder Reservoir WTP Construction Cost 231,000
Owner-PUrchased Forklifts (2) 53,000
Engineering Costs 133,000
Total ProJect Cost 799,000
"Supersack" System
Betasso WTP Construction Cost 463,000
Boulder Reservair WTP Construction Cost 318,000
Owner-Purchased Forklifts (2) 53,000
Engineering Costs 167,000
ToWI Project Dost 1,001,000
~'~ Includes design, bid phase services, construction administration, and inspection.
Table 3
Annual Operation and Maintenance Cost Differential for Dry Fluoride Use
Compared to Fluorosilicic Acid
Chemical Annual Cost Differential
1$)
50-POUnd Bag Manually Loaded System
Sodium Fluoride 11,500
Sodium Fluorosilicate (32,150)
"Supersack" System
Sodium Fluoride 6,600
Sodium Fluorosilicate (35,500)
~'~ Annual cost differential was calculated using the values in Table 1 and Section 3.3.
144922230 6 05/14/07
DRAFT
It is important to realize that the O&M costs can vary widely due to
unpredictable market values and supply of chemicals. A case in point is that one
of the suppliers of sodium fluorosilicate (KC Industries) informed Black & Veatch
that there is currently a shortage of fluorosilicic acid in the United States, and that
many WTP authorities have been getting emergency shipments of dry fluoride to
supplement their liquid fluoride feed operations. This has resulted in price
increases for the dry chemicals.
Lastly, discussions with suppliers indicate that it is somewhat rare to have
sodium fluoride delivered in "supersacks". This also could lead to a fairly
substantial variability in the cost of this chemical.
144922230 7 OS/14/07
DRAFT
APPENDIX A
DETAILED COST ESTIMATES
DRAFT
Table A-1
Betasso WTP Dry Fluoride Storage and Feed Construction Costs
(50-Pound Bag Manually Loaded System)
Item Quantity Unit Unit Cost Total Cast
(S) lS)
RENOVATION OF EXISTING SCRUBBER ROOM
Additional Steel Structural Support for
Existin Landin s 1 Lump Sum 1,500.00 $1,500.00
Demo of Existing Scrubber System
includ~n Chemical Dis osal 1 Lump Sum 30,000.00 $30,000.00
Concrete 20 Cubic Yard 550.00 $11,000.00
Loading Platform (includes Grating and
Fremin 40 Cubic Yard 120.00 $4,800.00
Handrail 30 Linear Feet 50.00 $1,500.00
Pallet Storage Racks 1 Lump Sum 3,000.00 $3,000.00
Door (6' x 8') 1 Lump Sum 3,500.00 $3,500 00
Connedions and Piping to Existing Feed
S stem 1 Lump Sum 1,500.00 $1,500 00
Electrical 1 Lump Sum 10,000.00 $10,000.00
Instrumentation 1 Lump Sum 13,000.00 $13,000.00
Dry Feed System 1 Each 76,000.00 $76,000.00
NEW STORAGE BUILDING
Structure 400 Square Feet 180.00 $72,000.00
Electrical and Heating, Ventilating, and
Air Conditionin 400 Square Feet 50.00 $20,000.00
SUBTOTAL E247,800.00
CONTINGENCY (40%) $99,000.00
ROUNDED CONSTRUCTION
SUBTOTAL E347,000.00
GENERAL REQUIREMENTS $35,000.00
CONSTRUCTION TOTAL 5382,000.00
A-1
DRAFT
Table A-2
BeWSSO WTP Dry Fluoride Storage and Feed Construction Cosis
("Supersack" System)
Item Quantity Unit Unit Cost ToTal Cost
ISI lSl
RENOVATION OF EXISTING SCRUBBER ROOM
Additional Steel Structural Support for
Existin Landin s 1 Lump Sum 1,500.00 1,500.00
Demo of Existing Scrubber System
includin Chemical Dis osal 1 Lump Sum 30,000.00 30,000.00
Concrete 10 CubicYard 550.00 5,500.00
Handrail 15 Linear Feet 50.00 750.00
Pallet Storage Racks 1 Lump Sum 3,000.00 3,000.00
Door (6' x 8') 1 Lump Sum 3,500.00 3,500.00
Connedions and Piping to Existing Feed
S stem 1 Lump Sum 1,500.00 1,500.00
Electrical 1 Lump Sum 10,000.00 10,000.00
Instrumentation 1 Lump Sum 13,000.00 13,000.00
Dry Feed System 1 Each 140,000.00 140,000.00
NEW STORAGE BUILDING
Structure 400 Square Feet 180.00 72,000.00
Eledrical and Heating, Ventilating, and
Air Conditionin 400 Linear Feet 50.00 20,000.00
SUBTOTAL 300,750.00
CONTINGENCY (40%) 120,000.00
ROUNDED CONSTRUCTION
SUBTOTAL 421,000.00
GENERAL REQUIREMENTS 42,000.00
CONSTRUCTION TOTAL 463,000.00
A-2
DRAFT
Table A-3
Boulder Reservoir WTP Dry Fluoride Storege and Feed Construction Costs
(50-Pound Bag Manually Loaded System)
Item Quantity Unit Unit Cost Total Cost
15) IS)
RENOVATION OF EXISTING SCRUBBER ROOM
Demo ExisUng Concrete Walkway and
Stairs 1 Lump Sum 1,000.00 1,000.00
Demo of Existing Scrubber System
includin Chemical Dis osal 1 Lump Sum 30,000.00 30,000.00
Concrete 5 Cubic Yard 550.00 2,750
Loading Platform (includes Framing and
Gratin 35 Linear Feet 150.00 5,250.00
Handrail 40 Linear Feet 50.00 2,000.00
Pallet Storage Racks 1 Lump Sum 7,500.00 7,500.00
Door (6' x 8') 1 Lump Sum 3,500.00 3,500.00
Connections and Piping to Exizting Feed
S stem 1 Lump Sum 1,500.00 1,500 00
Eledrical 1 Lump Sum 10,000.00 10,000.00
Instrumentation 1 Lump Sum 13,000.00 13,000.00
Dry Feed System 1 Each 73,000.00 73,000.00
SUBTOTAL 149,500.00
CONTINGENCY (40%) 60,000.00
ROUNDED CONSTRUCTION
SUBTOTAL 270,000.00
GENERAL REQUIREMENTS (10%) 21,000.00
CONSTRUCTION TOTAL 231,000.00
A-3
DRAFT
Table A-0
Boulder Reservoir WTP Dry Fluoride Storage and Feed ConsVUCtion Costs
("Supersack" System)
item Quantity Unit UnitCost TotalCost
~s- ta-
RENOVATION OF EXISTING SCRUBBER ROOM
Demo Existing Concrete Walkway and
Stairs 1 Lump Sum 1,000.00 1,000.00
Demo of Existing Scrubber System
includin Chemical Dis osal 1 Lump Sum 30,000.00 30,000.00
Concrete 5 Cubic Yard 550 00 2,750
Pallet Storage Racks 1 Lump Sum 7,500.00 7,500.00
Door (6' x 8') 1 Lump Sum 3,500.00 3,500.00
Connections and Piping to Existing Feed
S stem 1 Lump Sum 1,500.00 1,500.00
Electrical 1 Lump Sum 10,000.00 10,000.00
Instrumentation 1 Lump Sum 13,000.00 13,000.00
Dry Feed System 1 Each 137,000.00 137,000.00
SUBTOTAL 206,250.00
CONTINGENCY (40%) 83,000.00
ROUNDED CONSTRUCTION
SUBTOTAL 289,000.00
GENERAL REQUIREMENTS (10°/a) 29,000.00
CONSTRUCTION TOTAL 318,000.00
A-4
DRAFT
~
.~~
~~
~~ ~~
'; . ~~ ~
,
; --- -:;: ~ -,. ~ -_ _ _ _ _ ~ ~ ~,
~ ~„
~:
;. .
~
;~ ; ;
~~
;~ .. ~ v
's. ` s~
•~y s i .°~ .___ . ~ iln
i
~ ~ ; b .. ~ 1~ -- : ~
y ~ ~~' i ~
i ~~ 4
~ ~~~ ~~ ~ - ;
~~ ;
a , ~~ =~x
a .. ; ~~ ~~Q ~~ 8
~ ~ ~~ ~ ~
` ; ~ ~~
~ -
, ~ -_,;
, ~ ,-_._ . , - .
I 6.-O. ~ ~.,o. ' _ ' ~ ~ 81-~• I
r
i
,
~~~
~~N
~ a
-„ ~; e ~~ ~~ ~ CITY OF BOULDER, COLORADO
a
~
~ -. ~
m~ ~~~ DRY FLUORIOE FEASIBILITY STUDY .
»
ni ~~~
flENOV
r BLACK&VEATCH
~ _
_ SCRUBBEA AOOMiS
FOR
............ ....___ __.. _...---° ......__.. l4ek 8 Vwmh Corpxatlon
'w...ia..u.
- - -',.
~~
:~
b
~
$LOPE
G~I~~
.._" ".____."...: ~'.._' .. "... '.
'
~i